Sunscreen Application
防晒霜涂抹
英文原文
What Amount of Sunscreen Is Appropriate to Apply? The FDA and international protocols recommend applying 2 mg/cm² of sunscreen or 35 mL per application to adequately cover 1.73m², the average adult body surface area.This recom- mendation is well supported by numerous studies.In particular, a multicentre study found a linear dependence of the SPF on the quantity applied (0.5, 1.0, 2.0 mg/cm2) and concluded that 2 mg/cm2 is ideal. However, for the consumer, the 2 mg/cm2 measurement makes little practical sense. Stud- ies show that consumers typically apply much less, usually between 0.5 and 1.5 mg/cm2.The most important factor in the application of sunscreen is to apply a liberal quantity,and this is the wording used in Canada’s updated sun-safety messages.In children, Diaz and colleagues found that appli- cation with a controlled device such as a pump or squeeze bottle yielded higher quantity.Ou-Yang et al30 found sun- screens with SPF 70 and above may compensate for underap- plication by consumers.
对应中文
涂抹多少量的防晒霜比较合适？FDA和国际协议建议每次涂抹2mg/cm²或35ml的防晒霜，以充分覆盖1.73m²的成人平均体表面积。这一建议得到了众多研究的充分支持。尤其是，一项多中心研究发现SPF与应用量（0.5、1.0、2.0 mg/cm²）呈线性关系，并得出结论2mg/cm²是理想的。然而，对于消费者来说，2mg/cm²的测量几乎没有实际意义。研究表明，消费者的防晒霜用量通常明显较上述标准少，一般在0.5到1.5mg/cm²之间。涂抹防晒霜的最重要因素是涂抹量要适当，这是加拿大最新的防晒安全信息中使用的措辞。对于儿童，Diaz等发现，使用控制装置（如泵或挤压瓶）可以获得更高的防晒效果。欧阳等人发现，SPF70及以上的防晒霜可以弥补消费者通常用量的不足。
英文原文
Recommendation: Sunscreens should be applied liberally to all exposed areas. As a practical estimate to the consumer, approximately 45ml (the amount of 1 shot glass) would be more than enough to cover the entire body surface of most average-sized individuals, or 2-3 tablespoons for the body and 1-2 teaspoons for the face and neck.
对应中文
建议：所有暴露的部位都应该使用防晒霜。按照实际身体情况估算，大约45ml（一个玻璃杯的量）足以覆盖大多数中等身材个体的整个体表，或者具体如，2-3汤匙用于身体、1-2茶匙用于面部和颈部。
How Long Before Sun Exposure Should Sunscreen Be Applied?
在阳光暴晒前多久应该涂抹防晒霜？
英文原文
Several review articles state that sunscreen should be applied liberally to exposed sites 15 to 30 minutes prior to sun exposure.These recommendations are based on how the sunscreens were tested, as there was a complete lack of evidence to support this practice in our literature review. Sunscreen-testing protocols mandate drying times of 15-20 minutes before SPF testing can begin (to ensure water resis- tance): Mandatory labelling reflects this instruction. There are no data to suggest that there is a delay in sunscreen effi- cacy; in fact, a recent study showed sunscreen offered imme- diate protection when applied.
对应中文
几篇评论文章指出，防晒霜应该在接触阳光前的15到30分钟大量涂抹在即将暴露的部位。这些建议是基于防晒霜的测试方法，但在我们的文献综述中还基本没有证据支持这种做法。防晒霜测试协议要求在SPF测试开始前等待防晒霜干燥15-20分钟（以确保耐水性），强制执行标签也强调了这点。目前尚没有数据表明防晒霜的效果会有延迟；事实上，最近的一项研究表明，防晒霜在涂抹时可以立即提供保护。
英文原文
Recommendation: Sunscreen should be applied prior to sun exposure. It would be reasonable to wait 15-30minutes after application of sunscreen before water exposure to ensure water resistance.
对应中文
建议：防晒霜应该在暴露在阳光下之前涂抹。涂抹防晒霜15~30分钟后再暴露在水中是合理的，以确保防晒霜的防水性。
Is Sunscreen Harmful (ie, Risks of Compounds/Ingredients)?
防晒霜有害吗（即化合物/成分的风险）？
英文原文
Recommendation: There are no definitive data to support that sunscreen filters cause any toxicity in humans. There are some signals that there is a need for further study on the effect of certain UV filters on the environment. The SC appears to be an effective barrier against the penetration of inorganic zinc and titanium dioxide nanoparticulates; there- fore, significant systemic absorption should not be a concern. The most common adverse effect of using chemical sun- screens is the risk of photoallergy, and overall the prevalence is quite low. There is currently a lack of evidence to suggest sunscreens containing benzophenone filters lead to decreased fertility. Although a recent laboratory study suggests oxyben- zone may pose a hazard to coral, more research is needed, particularly because a direct association between sunscreen posing a threat has not been established, especially given its abundance in various other products.
对应中文
建议：没有明确的数据支持防晒霜对人体有任何毒性。有一些信号表明，需要进一步研究某些紫外线滤光成分对环境的影响。SC似乎是阻止无机锌和二氧化钛纳米颗粒渗透的有效屏障；因此，不需担心它们会被全身显著吸收。使用化学防晒霜最常见的不良反应是光过敏的风险，但总体来说患病率相当低。目前缺乏证据表明含有二苯甲酮滤光成分的防晒霜会导致生育力下降。尽管最近的一项实验室研究表明氧苯环可能对珊瑚造成危害，但还需要更多的研究，特别是因为它在各种其他产品中的含量很高、而防晒霜对珊瑚造成威胁的直接联系尚未确定。
Are Sunscreens Safe for Infants?
防晒霜对****婴儿安全吗？
英文原文
Health Canada recommends sunscreen use for children older than age 6 months and to consult a health care practitioner regarding its use in younger children (Health Canada 2015). Avoidance of sun and pro- tective clothing are the mainstay for sun safety in infants younger than age 6 months.
对应中文
加拿大卫生部建议6个月以上的儿童使用防晒霜，并建议如您有幼儿使用防晒霜的问题、应当咨询卫生保健从业者（加拿大卫生部，2015年）。对于6个月以下的婴儿来说，避免阳光照射和穿防护服是保证阳光安全的主要措施。
Does Sunscreen Prevent Skin Damage/Aging/Wrinkles?
防晒霜能防止皮肤损伤/老化/皱纹吗？
英文原文
Cumu- lative UV exposure is a major contributing factor in aging skin. Regular use of sunscreen protects against signs of photoaging, including rhytides, pigmentary changes, and telangiectasias.
From biopsy-specimen analysis, Phillips and colleagues concluded that daily use of sunscreen reduces UV exposure-related skin damage compared with intermittent use of equal or higher SPF products.Similarly, Seité demonstrated that daily moisturizers with broad-spectrum sunscreen protected against solar UV-induced skin damages in the epidermis and dermis and daily application prevents UVA radiation-induced transcriptional expression of genes that are directly linked to skin aging and also reflect the skin’s antioxidative stress defense response.
对应中文
紫外线照射是导致皮肤老化的主要因素。经常使用防晒霜可预防光老化症状的出现，包括皱纹、色素变化和毛细血管扩张等。通过活组织标本分析，Phillips等得出结论，与间歇使用同等或更高SPF产品相比，每天使用防晒霜可减少紫外线暴露相关的皮肤损伤。同样，Seité 等的研究表明，每天使用含有广谱防晒霜的润肤霜可防止紫外线引起的表皮和真皮层皮肤损伤，同时还可防止UVA辐射诱导的基因转录表达（这些基因与皮肤老化直接相关、也可反映皮肤的抗氧化应激防御反应状态）。
Does Sunscreen Prevent Skin Cancer?
防晒霜能预防皮肤癌吗？
英文原文
A randomized con-trolled trial of adult Australians80 found that after prolonged follow-up, squamous cell carcinoma tumour rates were decreased by almost 40% in people randomized to daily sunscreen use compared with those with discretionary use. Basal cell carcinoma tumour rates tended to decrease as well, but not significantly. Another randomized controlled trial found daily use of sunscreen prevents and/or retards the development of solar keratoses among adults.81 Moreover, regular use of sunscreen has been shown to be cost effective in NMSC and actinic keratosis prevention.Ten years after the Australian randomized controlled trial cessation, 11 new primary melanomas were identified in the daily sunscreen group and 22 in the discretionary group, showing that mela-noma may also be preventable by regular sunscreen use in adults。
对应中文
一项针对澳大利亚成年人的随机对照试验发现，经过长时间的随访，与不规律使用防晒霜的人相比，每天规律使用防晒霜的人患鳞状细胞癌的概率降低了近40%，基底细胞癌的发病率也有下降的趋势、但不是很明显。另一项随机对照试验发现，每天使用防晒霜可以预防和/或延缓成人日光性角化病的发展。此外，定期使用防晒霜在预防NMSC和光化性角化病方面具有成本效益。在澳大利亚随机对照试验结束10年后，每天使用防晒霜的实验组发现了11种新的原发性黑色素瘤，而在可自由支配使用防晒霜的组中发现了22种，表明在成年人中规律使用防晒霜也可以预防黑色素瘤。
Expiry Date
有效期
英文原文
The literature search yielded no published studies on the effectiveness of sunscreens past the expiry date. Thus, it may be logical to recommend use of sun- screen only within the expiry date to avoid any potential harm, although this is not supported by any evidence. Most sunscreen manufacturers also have a recommended period after opening (POA), which is the maximum duration over which the consumer may use the product after opening. Although the POA for many sunscreens is 12 months, the rationale is unclear. A study has shown that expiry dates relate to the conditions of sunscreen usage, storage, formu- lation, and form. All sunscreens sold in Canada require an expiry date on the label.
对应中文
文献搜索结果显示，目前医学科学界还没有发表关于过期防晒霜有效性的研究。因此，尽管尚无证据支持，仍然建议只在有效期内使用防晒霜可能是合乎逻辑的，以避免任何潜在的伤害。大多数防晒霜制造商也有一个开盖后建议使用期（period after opening，POA），即建议消费者在打开包装后使用产品的最长时间。虽然许多防晒霜的POA是12个月，但其原理尚不清楚。一项研究表明，有效期与防晒霜的使用、储存、配方和剂型均有关。在加拿大销售的所有防晒霜都要求在标签上注明有效期。
英文原文
When placed in temperatures ranging from −20°C to 60°C (−4°F to 140°F) for 8 hours, some sunscreens were shown to have phase changes and discolouration at the extremes of temperatures. However, it is unclear whether these macroscopic changes observed would decrease sun-screen efficacy.
对应中文
因在−20°C到60°C（−4°F到140°F）的温度范围内放置8小时后，部分防晒霜在范围内的极端温度下会发生相变和变色。然而，目前还不清楚观察到的这些宏观变化是否会降低防晒效果。
英文原文
Recommendation: Sunscreens should be stored at room temperature to ensure stability. There is a lack of evidence to support whether it is safe or unsafe to use sunscreens past the manufacturers’ specified expiry date or recommended PAO.
对应中文
建议：防晒霜应在室温下存放，以确保稳定性。没有证据证明在超过制造商规定的有效期或推荐的PAO后使用防晒霜是安全的还是不安全的。
How Frequently Should Sunscreen Be Reapplied?
防晒霜应该多久重新涂一次？
Does Physical Activity Affect the Frequency of Application?
体力活动是否影响使用频率？
英文原文
Several studies have addressed sunscreen reapplication. Heerfordt showed that double sunscreen application optimizes sunscreen use compared with a single application as the median partici-pant had applied between 13% and 100% more sunscreen at the selected skin sites after double application than sin-gle application. In a study of 30 office workers, where half were randomly assigned to having SPF 15-30 sun-screen reapplied after 3 hours, no significant difference in absorption readings (taken at 20 minutes and then hourly for 1-6 hours after initial application) was found in the reapplication group. Similar findings in a split-face design study by Rigel et al.found no difference in ery-thema with reapplication 2 hours after UV exposure in golfers. Bodekaer et al studied the persistence of sun-screens during physical activity, hot environment, and bathing during an 8-hour period and concluded that one application is sufficient to reduce erythema caused by UVB, although this is assuming the recommended formu-lation and amount is applied.
对应中文
有几项研究已经解决了防晒霜的再使用问题。Heerfordt表明，与单次涂抹相比、双次涂抹可优化防晒霜的使用，因为在选择的皮肤部位，中位参与者在双次涂抹后比单次涂抹多涂抹13%到100%的防晒霜。在一项对30名办公室工作人员的研究中，一半的人被随机分配到3小时后重新使用SPF15-30防晒霜，在重新使用组中，没有发现吸收度数（在初次使用防晒霜后20分钟，然后每小时使用1-6小时）有显著差异。Rigel等人在一项分脸设计研究（split-face study）中的类似结果表明，高尔夫球手在紫外线照射2小时后再次使用时，没有发现任何差异。Bodekaer等人研究了8小时内体力活动、高温环境和沐浴期间防晒霜的持久性，并得出结论，一次使用就足以减少UVB引起的红斑，尽管这是假设使用了推荐的配方和数量。
英文原文
Recommendation: If the appropriate amount of sunscreen is initially applied, reapplication is necessary only after activities that may remove the sunscreen layer, such as swim-ming, sweating, and friction. There is no clear evidence to suggest a specific frequency of reapplication in the absence of these activities within an 8-hour period.
对应中文
建议：如果最初涂抹了足量的防晒霜，在游泳、出汗和摩擦等可能会去除防晒层的活动之后、必须重新涂抹。在8小时内没有这些活动的情况下，没有明确的证据表明重新使用的具体频率。
REFERENCES
1.Li H, Colantonio S, Dawson A, Lin X, Beecker J. Sunscreen Application, Safety, and Sun Protection: The Evidence. J Cutan Med Surg. 2019;23(4):357-69.